First off, its the old school RPGs that got me into playing games like EQ/WoW in the first place. Anything by New World Computing was gold like Anvil of Dawn and Might and Magic 3-5 (6/7 weren't bad either). Stonekeep was another good one, innovative and crazy graphics for its time. Ahh, back when nearly all RPGs felt like DnD with a particularly sadistic DM...

Albion was fun too, and so was the Dig and of course Monkey Island. I also liked the more comedic adventure games like Woodruff and the Schnibble and Torin's Passage.